MASTER OT J203749.39+552210.3 - is a new
cataclysmic variable (dwarf nova) in outburst, likely a superoutburst

MASTER-Amur auto-detection system discovered OT source at (RA, Dec) = 20h 37m 49.39s +55d 22m 10.3s on 2012-10-22.49793 UT.
The OT unfiltered magnitude is 14.1m (limit 18.6m).
The OT is seen in 2 images. There is no minor planet at this place.
We have reference image without OT on 2012-10-05.52608 UT with unfiltered magnitude limit 18.7m.

This object is identical to the faint blue star visible on Palomar
plates. It is present in GSC 2.3.2 with coordinates 20 37 49.310 +55
22 09.65 and magnitudes Fmag=20.38, jmag=21.31. Nothing is present at
this position in USNO-B1.0, 2MASS, 1RXS, GCVS catalogs and AAVSO VSX.
This area of sky is not covered by SDSS, GALEX and CSS. No previous
outbursts were detected on 12 Palomar plates taken from 1952 July 30
to 1994 Aug. 14, as well as on 3 Palomar/NEAT images of 2002 Sep. 23.